Alternator

I use a Denso 90 amp unit from a Bobcat on my car. One wire deal with fabbed brackets mounted low on the left side. You really should run an alternator, I see guys at the track all the time dragging around battery chargers and having to charge the battery after every round, looks like a PITA to me. Plus with an alternator you'll have good voltage all the time for the ignition and electronics, fuel pump, etc.

For the kill switch to work properly you'll need to run the battery wire for the alternator through a heavy duty relay, check out Painless Wirings HD relay for that.